This invention relates to a connecting device for detachably joining two boards or panels in a perpendicular relationship to each other, particularly furniture panels, in which the first panel is fitted with a fastener bolt having a head set apart from the shank by a circumferential groove and the second panel is provided with a first blind bore for rotatably receiving a cylindrical tightening member. The fastener bolt is inserted into a second blind bore provided in the second panel, whereby the axis of rotation of the tightening member and the axis of the first blind bore receiving such tightening member are perpendicular to the longitudinal axis of the fastener bolt and the second blind bore and are lying in the plane extending through the longitudinal axis of the fastener bolt and the first blind bore receiving the fastener bolt. The tightening member is in operative engagement with the head of the fastener bolt in such a manner that, as the tightening member is rotated, the fastener bolt is pulled into the appropriate blind bore, whereby the two panels are joined. Except for the grooved bolt section, the shank and the head of the fastener bolt have the same diameter.
The tightening member is provided with a tightening bore extending transversely to its axis of rotation and providing a proper fit for the head of the fastener bolt, and with an adjacent tightening slot the edges of which extend into the grooved section of the fastener bolt.
A detachable connecting mechanism of this general type is disclosed in German Patent Specification DE-OS No. 22 02 906. In this disclosure, the tightening member is in the form of a latch embracing the head of a fastener bolt from both sides with tightening discs or plates parallel to the plane of the second panel and guiding the bolt head in a circumferential slot. As the tightening latch is rotated, a force component acts also on the fastener bolt in the direction of rotation of the latch, which leads to a displacement of the bolt along its longitudinal axis with respect to the axis of rotation of the tightening latch. This has the result of the second panel being shifted sideways from the first panel during the tightening procedure. Moreover, in order to obtain a sufficiently large tightening distance, the diameter of the tightening latch must be substantially larger than the diameter of the fastener bolt.
German Patent Specification DE-OS No. 30 28 684 discloses a tightening member likewise in the form of a bolt. However, the type of tightening member taught by this disclosure requires a specific lateral relocation of the blind bores in the second panel.